In certain cellular radio telephone systems, a plurality of fixed radio stations or base stations share a common frequency channel called a control channel in the time domain, and transmit sequentially on this channel in respective time slots. This type of system is used when there is a lack of radio channels, and the traffic density is low. In such radio telephone systems, each radio telephone responds only to the control signal transmitted by the base station to which the radio telephone has registered, and signals back to the system (to the exchange) only via this particular base station during the reception of the control signal.